Dual coil guidewire with radiopaque distal tip

Abstract

A guidewire having a centrally located core wire about which is mounted a single outer helical coil spring. The core wire is typically longer than the outer helical coil spring, with the helical coil spring and core wire having common distal ends. The spring is brazed at both its distal and proximal end to the core wire. The distal brazing of the core wire and helical coil springs is rounded. A second small radiopaque helical coil spring is fitted in the distal end of the outer helical coil spring and may be brazed to the core wire and outer helical coil spring.

What is claimed is: 
     
       1. A guidewire comprising: a core wire having proximal and distal ends;   at least a first helical coil spring fit about said core wire, said helical coil spring having proximal and distal ends, with said helical coil spring proximal end secured to said core wire at a location distal said core wire proximal end, and said helical coil spring distal end secured to said core wire distal end; and   a second helical coil spring dimensioned to fit within said first helical coil spring and having a distal end and a free proximal end, said second helical coil spring at said distal end thereof being located at the distal end of said first helical coil spring, said second helical coil spring formed from a radiopaque material.   
     
     
       2. The guidewire of claim 1 wherein said second helical coil spring is from two to four centimeters in length. 
     
     
       3. The guidewire of claim 1 further including a rounded tip portion at said distal end of said helical coil spring and core wire. 
     
     
       4. The guidewire of claim 3 wherein said tip portion is secured to said distal ends of said core wire and first helical coil spring. 
     
     
       5. The guidewire of claim 4 wherein said second helical coil spring is formed from Rhenium, Tungsten, Tantalum, Platinum or Gold. 
     
     
       6. The guidewire of claim 1 wherein said second helical coil spring is formed from Rhenium, Tungsten, Tantalum, Platinum or Gold. 
     
     
       7. The guidewire of claim 1, further comprising: a rounded tip portion at said distal end of said first helical coil spring and core wire,   wherein said second helical coil spring has proximal and distal ends, and   wherein said distal end of said second helical coil spring is secured to said tip portion.   
     
     
       8. A guidewire comprising: a core wire having proximal and distal ends;   at least a first multilayered helical coil spring fit about said core wire, said helical coil spring having proximal and distal ends, with said helical coil spring proximal end secured to said core wire at a location distal said core wire proximal end, and said helical coil spring distal end terminating short of said core wire distal end;   a second helical coil spring fit about said core wire, said second helical coil spring having proximal and distal ends, with said second helical coil spring proximal end secured to said first multilayered helical coil spring distal end, and said second helical coil spring distal end secured to said core wire distal end; and   a third helical coil spring dimensioned to fit within said second helical coil spring, said third helical coil spring located at the distal end of said second helical coil spring and secured to said second helical coil spring and said core wire at a location proximal said distal ends of said core wire and second coil spring, said third helical coil spring formed from a radiopaque material.   
     
     
       9. The guidewire of claim 8 wherein said second helical coil spring is from two to four centimeters in length. 
     
     
       10. The guidewire of claim 8 wherein said second helical coil spring is formed from Rhenium, Tungsten, Tantalum, Platinum or Gold. 
     
     
       11. A guidewire comprising: a core wire having proximal and distal ends;   a first helical coil spring fit about said core wire, said helical coil spring having proximal and distal ends, with said helical coil spring proximal end secured to said core wire at a location distal said core wire proximal end, and said helical coil spring distal end terminating short of said core wire distal end; and   a second helical coil spring of radiopaque material having a distal end and a free proximal end, said second coil spring being fit about said core wire between said first helical coil spring and said core wire with said distal ends of said first and said second coil springs generally radially aligned.   
     
     
       12. The guidewire of claim 11, further comprising: a rounded tip portion at said distal end of said first helical coil spring and core wire,   wherein said second helical coil spring has proximal and distal ends, and   wherein said distal end of said second helical coil spring is secured to said tip portion.   
     
     
       13. A guidewire comprising: a core wire having proximal and distal ends;   a first helical coil spring fit about said distal end of said core wire, said helical coil spring having proximal and distal ends, said helical coil spring proximal end secured to said core wire at a location distal to said core wire proximal end and said helical coil spring distal end being secured to said core wire at a position disposed adjacent to said core wire distal end;   a second helical coil spring having a distal end and a free proximal end, said second coil spring being fit about said core wire and disposed between said core wire and said first helical coil spring; and   said distal end of said second helical coil spring is secured at a position adjacent said distal end of said core wire.   
     
     
       14. The guidewire of claim 13 wherein said proximal end of said second coil spring is secured to said core wire. 
     
     
       15. The guidewire of claim 13 wherein both of said proximal and distal ends of said second helical coil spring are secured to said core wire. 
     
     
       16. The guidewire of claim 13 wherein said second helical coil spring is formed from a radiopaque material. 
     
     
       17. The guidewire of claim 13, further comprising: a rounded tip portion at said distal end of said first helical coil spring and core wire,   wherein said distal end of said second helical coil spring is secured to said tip portion.